This is a vintage 1984 ProCo “The Rat” electric guitar effects pedal. This particular large/big box example, serial number RT-021116, is in very good all original condition. This ‘filter’ knob (post tone) version features the desirable LM308N chip, with all potentiometers indicating an early ’84 production. It is missing the (4) original tall profile feet, but is otherwise very nice. This is a fantastic sounding distortion pedal, with a substantially full-range sonic spectrum.